Search results for "Matrix"
showing 10 items of 3205 documents
Hematologic malignancies: The exosome contribution in tumor progression
2020
Abstract The bone marrow, composed of cells, extracellular matrix, and soluble factors, such as cytokines, chemokines and signaling molecules, provides a favorable microenvironment for hematologic tumor progression and for the development of drug resistance. Recently, extracellular vesicles (EVs), released by tumor and surrounding cells, have emerged as important players within the bone marrow niche. Here we will discuss the current knowledge on the EV- mediated crosstalk between tumor and normal cells, in order to better understand how vesicles can contribute to tumor progression. Advances in the knowledge of the role of cell-derived EVs in tumor microenvironment highlight the possibility …
Multi-mycotoxin determination in barley and derived products from Tunisia and estimation of their dietary intake.
2017
A study on raw barley and derived products (barley soup and beers) was carried out to determine the natural presence of twenty-four mycotoxins by both liquid chromatography and gas chromatography coupled to tandem mass spectrometry (MS/MS). The developed multi-mycotoxin procedure was based on both SLE and QuEChERS extraction steps. 66% of analyzed samples presented mycotoxin contamination and only one sample, which was soup of barley (6 ng/g), exceeded the maximum level (ML) established by EU for OTA (5 ng/g). Raw barley was the most contaminated matrix (62%), which concentrations ranged from 1.70 to 287.13 ng/g) and type of detected mycotoxins (DON, 15AcDON, NEO, NIV, HT2, FB1, OTA, ENA, E…
Behaviour of the plasma concentration of gelatinases and their tissue inhibitors in subjects with venous leg ulcers.
2015
Venous leg ulcers are common in subjects with chronic venous insufficiency. The increased intraluminal pressure causes alteration of the skin microcirculation, leukocyte activation and release of proteolytic enzymes leading to ulceration. An impaired expression and activity of matrix metalloproteases (MMPs) and their tissue inhibitors (TIMPs) might influence extracellular matrix degradation and deposition in chronic venous ulcers with the failure of the healing process. Our aim was to evaluate plasma concentration of gelatinases (MMP-2 and MMP-9) and their inhibitors (TIMP-1 and TIMP-2) in subjects with venous leg ulcers before and after the compression therapy. We enrolled 36 subjects (12 …
Ultrasonic phased array inspection of wire plus arc additive manufacture (WAAM) samples using conventional and total focusing method (TFM) imaging…
2018
In this study, three aluminium samples produced by wire + arc additive manufacture (WAAM) are inspected using ultrasonic phased array technology. Artificial defects are machined using a centre drill, ø3 mm, and electro-discharge machining (EDM), ø0.5-1 mm, in a cylindrical through hole topology. The sample was first inspected by a single element wheel probe mounted on a KUKA robot in order to investigate the feasibility of using a conventional ultrasonic transducer approach. Unfortunately, the wheel probe was found to be unsuitable for scanning of the WAAM specimens and ultrasonic phased arrays were employed next. The setup included 5 MHz and 10 MHz arrays (128 elements) in direct contact w…
New Insights into the Anterior Complex
2020
<b><i>Objective:</i></b> To introduce visualization of the germinal matrix (GM), external angle of the frontal horn, and periventricular white matter while evaluating the anterior complex (AC) during basic ultrasound assessment of the fetal brain. <b><i>Case Presentations:</i></b> This is a retrospective observational study of healthy women with singleton pregnancies, with no increased risk of fetal central nervous system anomalies, attending routine ultrasound screening at 20–32 weeks’ gestation. Seventeen cases are presented in which an abnormal aspect of the GM or external angle of the frontal horn or periventricular white matter on AC eval…
Reconstruction of Peritoneal-like Structure in Three-Dimensional Collagen Gel Matrix Culture
1997
The peritoneum is a serous membrane consisting of different kinds of cells and extracellular matrix components (ECM). The aim of the present study was to develop a three-dimensional (3D) in vitro culture system for possible investigation of pathological conditions of the peritoneum. Human omental mesothelial cells (MC) and endothelial cells from the umbilical vein (EC) were cultivated either on (MC) or in (EC) a preformed type I collagen matrix. In 3D culture mesothelial cells showed their phenotypical in vivo characteristics and the synthesis of a new basal membrane (BM). Endothelial cells developed vessel-like structures, produce a BM and express E-selectin after TNF-alpha stimulation. Th…
Protomylonite, Mylonite and Ultramylonite
2009
The objective of this chapter is to show how variation of strain intensity can be judged in thin section. Usually this kind of variation can best be observed in low-grade mylonites where the percentage of porphyroclasts decreases progressively with strain intensity. However, the percentage of matrix is highly dependent on mineralogical composition (e.g. quartz and biotite tend to convert to matrix readily). Compositional banding in gneiss can therefore result in mylonitic banding of apparent strain variation, which in fact only reflects variation in composition of the parent rock. Several examples of ultramylonite are derived from quartzitic rocks that tend to form few or no porphyroclasts …
Deep conservation of bivalve nacre proteins highlighted by shell matrix proteomics of the Unionoida Elliptio complanata and Villosa lienosa.
2016
The formation of the molluscan shell nacre is regulated to a large extent by a matrix of extracellular macromolecules that are secreted by the shell-forming tissue, the mantle. This so-called ‘calcifying matrix’ is a complex mixture of proteins, glycoproteins and polysaccharides that is assembled and occluded within the mineral phase during the calcification process. Better molecular-level characterization of the substances that regulate nacre formation is still required. Notable advances in expressed tag sequencing of freshwater mussels, such as Elliptio complanata and Villosa lienosa , provide a pre-requisite to further characterize bivalve nacre proteins by a proteomic approach. In this…
Min-max control of uncertain multi-inventory systems with multiplicative uncertainties
2001
In this note, we consider production-distribution systems with buffer and capacity constraints. For such systems, we assume that the model is not known exactly. More precisely, the entries of the matrix representing the system structure may be affine functions of some uncertain time-varying parameters that take values within assigned bounds. We give stabilizability conditions that can be checked, in principle, by solving a min-max problem on the surface of the state-space (buffer level space) unit ball. Then, we consider a special case in which each uncertain parameter affects a single column of the system matrix and is independent of all the other ones. In this case, we propose a mixed int…
Association of AUUUA-binding Protein with A + U-rich mRNA during nucleo-cytoplasmic transport
1992
Resealed nuclear envelope (NE) vesicles from rat liver containing entrapped exogenous RNA were used to study the effect of adenosine+uridine binding factor (AUBF), present in cytosolic cell extracts, on ATP-dependent transport of A+U-rich RNA (AU+RNA) and A+U-free RNA (AU-RNA) across the NE. This factor specifically binds to A+U-rich sequences present in the 3' untranslated regions of lymphokine and cytokine mRNAs, containing overlapping AUUUA boxes (granulocyte-macrophage colony stimulating factor, interleukin-3). Addition of AUBF to the extravesicular compartment markedly increased the efflux of the in vitro transcribed, capped and polyadenylated AU+ RNAs. Export of entrapped AU- control …